In 3GPP long term evolution (LTE), an uplink power control algorithm of a physical uplink shared channel (PUSCH) uses a method of combining open loop power control and closed loop power control, where the power control is classified as the open loop power control and the closed loop power control according to whether the mobile station/terminal and the base station are involved simultaneously. Currently the closed loop power control is mostly used to compensate the error of the open loop power control, so as to archive precise control of channel fading under a frequency division duplex (FDD) mode.
For PUSCH transmission, taking control signaling overhead into account, a 2-bit transmit power control (TPC) command is used to indicate the closed loop power control which includes an accumulated mode and an absolute mode. Currently, in the accumulated mode, a TPC command supports a raise by 1 dB and 3 dB, that is the power may be increased by 1 dB or 3 dB on the basis of the power of last transmission; the TPC command supports a decline only by −1 dB, that is the power may be decreased by −1 dB on the basis of the power of last transmission. The advantage is that when channel conditions or other conditions change, the transmit power of a UE can be quickly increased so as to adapt to the channel conditions.
Because a physical downlink control channel (PDCCH) uses only 16-bit cyclic redundancy check (CRC), and the UE performs PDCCH blind detection up to 44 times in every transmission time interval (TTI, unit: ms), when the time is accumulated comparatively long, for example 1 s, the probability of false alarm or erroneous detection will increase greatly. Here the false alarm may be understood as a base station does not send a PDCCH, but the UE detects the PDCCH. Since in the accumulated mode, four code points have equivalent status, it can be assumed that the probability of false alarm for the TPC Command Field (TPC control command field: 0,1,2 or 3) is the same, noticing that the accumulated mode supports a raise by 1 dB and 3 dB, but supports a decline only by −1 dB, then in the statistics of certain time of accumulation, the power of UE is increased unnecessarily due to the false alarm or erroneous detection of the PDCCH, which will cause unnecessary power waste and uplink channel interference, and thus affects uplink performance.